SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c93d293eaf73630682789fdf550de09a611267c7d08afad1c6650fafa15d2a0a' 
  AND token = 'Fal8CB74xhZXflIRnZ/YEdwil1SvW3zjey75uJMAsjk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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