SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1bed6743342f2b3682aecad0f827a2778e005f8fcc202d21d2c240e7bf32a011' 
  AND token = 'xT+WmtFHSxipyLbBQHjQSdL3uhHjNc2ifxSWuFmZVRc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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