SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f8addfe6140155deb0dd8c32446be4271a31009149932e475852fabe84b0cdb' 
  AND token = '/uquAfUXECfb0fuOrhox9vp/fP0MRZH1rYCaMzvrs6Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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