SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9933dfdd0b83fbccbea65916fdf05ba70911b3ec85d308a23504aca1b3e33803' 
  AND token = 'EJ3ougcFDIhe7+IkMeBHbAleGALrByKsTVi4ommhH2o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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