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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c346a9757cb721f1a3239fd9389e72c3a11b07c79b57562eb14e25f841d1c64' 
  AND token = 'VjlUgdjrOg8FfCRXxDebckRDziFzpj/M8IXeVIBh1g0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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