SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f9d71c0fcf18317d5900082c1657d0bc68599371eb0e29626ff94d158e4950b8' 
  AND token = '0roDxR+P8umhAUgvL2XyD4lJW/HQaYu0ilIVjeFuzIg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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