SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce312ad9faa670c83b4ef784f59bb157d3f2c085cbca5915bd9aabf973edc914' 
  AND token = 'IafsywsYHEcLbvlxnbm7d5F4/PLDJyRxNSfhDSYHX2c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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