SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2707d5af59edc6181590758243799ed747bd06c64da39719e8d2a2555bdd5bdd' 
  AND token = 'xQfkvEl+CJOQiczocMue+MuaNGH+eM0rhCEs1VgDTHA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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