SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e64160ea96e34ba7911f0c0b21ef6a4ded498758b1bd2156e235abc2af9ec602' 
  AND token = '5nMFMTqqZUmHzWlNVEJOzGOZopdOrSziBmDpkPEtiLU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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