SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2efba18b2b225b50f56f9056889a00013e0959cac966751bbc7411cb8b43887' 
  AND token = 'hQ7Qfy0kLc7FeK/J5voaJHjjE4+wDjOubINZmLfaGrg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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