SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f730e78755d385bef46f2685ea3cd14a097a9ce9714ed3f4feaf26c0ecb2a29b' 
  AND token = '0wujKppBEbBiqQKWjSIRyUQ7REfG9GsSGSdV0hdv2Zg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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