SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5622dfaa0a64ab177676caa4cb4a911ccf4494a4c0661dfc2283e58b045a0565' 
  AND token = '8Nk5ZBJkj0YLR3/p7Eh8B8yhgVvwIbnxAhkPLGAo++c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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