SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b054c6e0412ec01206048f8d8d82521b320e7c02f64a9e685736f0779660bf55' 
  AND token = 'E9a3z1tBRcC5hmF5bDHrq4KN7lPFZrfFhY5ceglUepw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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