SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86a79774e0ba905d1c1690bb2ac26807026acae6317ee4c27023676196fda26c' 
  AND token = 'GNYn2zvSz0z+bL4D36yZP4uy6vAghvWDWyIH+YFyXks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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