SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8ceb704e3b119a16b7c8924a4ad44fb803183f69b81337a2f6a95bf5dc07df3' 
  AND token = 'zXbmVFOtfOjAnfBO9/513bcfUr81RjQJc87WU25eOFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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