SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7e1043aeaa483163d9d3e46049f4c73259060261622c2a5dd4a0f11b3d94487' 
  AND token = 'pTY1qXQs6BsfHZVfe5Vax7TT44y/RqWRlzL3m4psSNY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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