SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b56a16890b02a1cfaeea9cea05f721f1204e02878c78bb23e30b9f13faca46a2' 
  AND token = 'dyvIAWmNwPwJv8I053Q9/tDF3UKp1vdFqLvPETJcYnI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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