SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f3ebfd0c77f38d06f840301b3599df6e834dc93dfc20bc0602d60ad2a23c12d' 
  AND token = 'FRWfccNSwuMsG9tBTtOimxElPNJbhudn/nXyXFwY+yY=' 
  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"
    }
  }
}