SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f11be2fb0e1775c7ed2174bc965531e5ef4d87b96bf9e6b27bf6a09872af4996' 
  AND token = 'I7y7W8ARl2zlLpqO9SC9HeVXTkbWCS1tMU5HPhdPz7k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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