SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2df4f92906a8eab103ee31ee8fa4b9801dc089b0a8e401653edac66bef90c9b' 
  AND token = 'I9Q8AUL2v3vogW1FIXiURixjhBCCNOli+FD4TpZwSgM=' 
  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"
    }
  }
}