SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0512044d1f9615aeb0efd43bbdda51004b193002d6aa06d192c3c72106c2dba5' 
  AND token = 'r3eZ8LSUZAZZj9VgrsEKsc+R9QJyBXaYVYYs0QcDlvs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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