SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06f194a290ba07bb3e61e735b0e48f965deafd9571f2e14768171cffc2eea51d' 
  AND token = 'eO6OGdkdpVgnkB1g97LlwskRvMB2XaTTBd9Su2ciN8U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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