SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7f62095ca5df5f99c40b7cfa723147ac1631da0cc886387939d76f7f7d47afd' 
  AND token = '4Cv7AquJg+VbuBEEMECxuBWjs2nnlNwga+hTdFnoBGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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