SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5334d050c88dfe1add5539862cce2502bf14101c6abf1815982efe10e9e08ff8' 
  AND token = 'jY31OynJFyE7IfgQ3bLPE4R7oL4Tw327OYkMLN2QXO0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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