SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64e76525ed1853e3f3d639b150140fea0e355a68deec1df541810970b3298205' 
  AND token = 'RqASa05wL4PInftw+hJNVFAk1Ixnf0mHwVwN87HHBvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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