SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0eeb47c3d56c5005d4468814eff0b47b3de7d0826ec3af399c55fa9ced451d6a' 
  AND token = 'qzBNZ+bdcn91DOBlXE5FhZ5AQT4e7g2qbwxaTeaH/6Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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