SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '07ae5a8c741a37f6b114aeabc2d69549643f0f20f3330392d5b3747afc49a889' 
  AND token = '5Nuhg9yCS2ddK3DJ7A3n91NxkGVuOQYmQj944wJV83c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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