SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38eed85a809eb984c61fb222148ca63084ce6acbbce7b034c311ef4c982ee6d4' 
  AND token = 'FkPdidPutfpk/Z9L+mb7M5rJXz4tHfEhbeMUvNipiZ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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