SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d6812568585bcd4b64f0221126a50164bcfd2c54191448d7b0b1caaa2012d24' 
  AND token = 'ybcQsQXgowRURUDwq3ppIVmln3vshWEeDs+Q/WRcmpk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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