SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c038db6a0eeb40871ef16e67651340acac24a89829146637bdcf49af9dde8021' 
  AND token = '/gH+r3OiUdm6rcAvaStzrvTJJvojTavgM6p8P/MbpTs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}