SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f074f6e15afcf83101cf981d2572ecf9fcbf36f5336df4b4d5adee89c1b5e455' 
  AND token = 'TNMXJB0G+LUzDPvAML6th0acKv9mJ7/I/rGVHI8kJBA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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