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SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'a315f05ebf8e365d15c909ba395a0710f0afa67e6aabc9130144c360c854875d' 
  AND token = 'FVa74El7tvfsnSOgFStrGlH/+ICTGrQ70NZLcUymGrA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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