SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f5cfd61bf6783bc2e1d6221b1fad367c4925a58d2c94387f3afa8ebb8bf28d8' 
  AND token = 'veqVEt7njdGH99wgju7muQw9dzp362HVRHa09Wogh/k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00255

JSON explain

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