SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85f5ff71d7b3a3bb2713c0eafdedeea4660a567d5db14e93ebe84a703ec96993' 
  AND token = 'CAaEPLZYYPV1MecGPLkUmolO76DntxiPgN4q6svohNM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}