SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2acb202a160df64c33fd380cde0fe191de0737fa4b0483d3b33782bf80d2128' 
  AND token = 'pzp1Jg9zghvD+UjErHej3+XsRghfP9ujX4EWdLwDgF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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