SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c897c88a24134d97284365c910118af578b517c6dcb0fff2f8e3535b2d249352' 
  AND token = 'GjkHWVAKWq6Bww383toUw51k5592X0M/sEFxZ17g4No=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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