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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a75b826db911e3a1b1cbd37d67f42e68cdfa6afd9ebe4df6af2c2e74750f0f7' 
  AND token = 'v7ZSNJLMc9a+JKADJkM6s5PytM3E8uWs1nLzqxZNFgo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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