SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'becf59d730385ce33b8039bae1be2f0335bf75e4ff14ecd231fb838df6f2e37b' 
  AND token = 'rGql/E1+m+MxjeqXydhtzbF6VEWChkkUtwGHgDXxWaM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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