SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d7635457ec33312919c4746a9f6530c15f388d1819dac6ace9e4521f3f043b0' 
  AND token = 'zNFkfJim2GKskDpc9ynXm/ltYH/Q9RgTU8yLZ4YCxCA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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