SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52d177e3f3851b488c923d0f428fb6201cf2dcd1f6119c5c366c2471dd12084c' 
  AND token = 'OR1B/5CuzUtFzxjGtlRwgq6+F8P5ybztzz/BS6YdYeE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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