SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '952529420fedc45888e4034bb242fd55ff25fc0ae84a3413c42f0a4d3ca1419d' 
  AND token = 'dFSeRE590pSC+/LYMQ3o1+jCnc6vgdYL09GJC+jGpx8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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