SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f3a14884ec3c05525fa866b6fd17295460cbb5722d7f2f290dfc7b03088e7294' 
  AND token = 'DhxfcJecLsAG+Jvqp2Y565Y2D0KXFq3PiJQdU7kobSg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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