SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '556fc025d93d5b819421ec42100683b47104432c3ba753e0b2b2013cb6b74cfb' 
  AND token = 'J9imS01jZ9BsvckTxU8DZmO4kJ/qbCFLPXNuHpSYF0M=' 
  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"
    }
  }
}