SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a7529389418317ab602af7836c3d292ec6be5087be4390483c20a74f79219ba' 
  AND token = 'C9BrvThiGlQ8vO+6BaPxovhjZ/wK8XAYAJyT9BA3MTw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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