SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1c112c2eb7afcf2660c5e35701c09017b2fc318327f410418105e8d88cc99e7' 
  AND token = 'QVAVLqIWCTBkWP2CgYvO8Z5FRMHp/b0QHbkdebeYybI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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