SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2f63181a8eb21bb3b29ef592f499b6eca3717defcbca1a90994f6b176b5cdb6' 
  AND token = '4pQo8P2rXltXJDCXYM2h497E4xsNAjPobSK7Q/mDln0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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