SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ee74cb8aac7c30ad085246b791560fea06cfda007a6b9136062d75723e3786a' 
  AND token = 'DH/XpF5nS6vM5VCoT+v7dLaPTtXjMAhypgGL7m4kVag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}