SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '211560267e0aa832144ca19208e031b78dc2b094bb118701cd23722e63124d24' 
  AND token = 'rLiZLtwEepFQPsmlVrfE/OcvHD/q2/+qC/zYY/BKsJ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}