SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b6e0f31b4c174456a79cbe83ad841172beb202eb886f122fc3403bcbd4b2c64b' 
  AND token = 'crMIbuj+lUtAGRz/NP8jyqp3Cka70Fa4jEpTYtY1GII=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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