SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32f99caf4721c3e2299be31a14acdceea944d59cc814bed48e155365858e6b2c' 
  AND token = '1DDG/d+pqFrCRtmmIM0k2nmnwcuvCnvgzEDBqQvk6pQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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