SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbe93aeeb5b5cdd39f980552eaf0f879e1a40676364b922eb38ab2802103b05c' 
  AND token = 'jtSqJhVD+fvHnkC1FYQHwCelKJZCfL//VFuD5jF/pvo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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