SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '267fd87240fc2b5756c355faa20b085f01549abc98f92eba1c6e40525bd28c7e' 
  AND token = 'SZt/NFBkQ5vuGpipYpOmbqkuD6JPN4/OwCHzq4MiK3o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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