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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8334a79229d83ad1af8b6b8df4b0cc2ddcce1cc7fdaf12915ef3e81b4833ced3' 
  AND token = 'RvtRf5vBFsk327EbIoJ3RJ+jV3BmFTXGsDWBJQJujE8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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