SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0330ae8260f5cfc85f787790afaaad88870d9bedaa25d5f2cade86fe8dbd391' 
  AND token = 'nMGawLPQ2dlme8wwPUxZCfq7MZyR83rvhm2F1ejxBWE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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