SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '77236ded080b64c1ddc4f84a1cbc5aea9babe2f4114c25401076a7b00841f619' 
  AND token = '+nIi6JH/FW+8VfFbRPw2NT1cdo0RP1MSqbZiuhKLpn4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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