SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '55e7e3390fcf691466676751fabeb5b8803897d80a798ece3a083606f35f7d03' 
  AND token = 'lSPzAaiM1QaTxTRxThwuN/wgAL+DKaMZrBUQWx+9lzc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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