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SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '581e64760fdedb7a30f0688c295ca7dc1e9c1f5cc5a69d04501dcdc82af1924d' 
  AND token = 'Z25ZcNnzfTmKE3g4DdhEbJNbZM4IQqFwHh4DegQgFD0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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