SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4ecf280645f6deae5fad04cb05f28bcd61367348d29fc462753cff443ec9df6f' 
  AND token = 'jyPsuYwour2rVyB15ienbZlAxUcK95iL6+RzD9KmBKg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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