SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfa1adab27452279485112b39d95667eb83ed0fde386c4380d2a926659d0d41c' 
  AND token = 'oM/fnVb4aZ7d7MnHR0KR2nLfe287jVzHlZO56qcim9c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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