SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4fe9c1fc8f7cf3fd7b098e74e4f2592b3ea13414767f7e58eac0af88fece658e' 
  AND token = 'pyvm3zJFZgufM4l6UPI0z686Qc+8dt9Ah3pnGEcZbFA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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