SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b08af5dda912535524d966b2bea3b90e3d3e43653cb160ad35e2d930ee16acbf' 
  AND token = 'ebtO4d7mX0r7mQLhQTwF0YXypdpaTlQL7GHDuFhoBVE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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