SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a182c2fa02b65bc57f214ba22c992eaf88c55110c3e5c591351208a695156518' 
  AND token = 'yAi4PhWHMgaSCbbfvOT6uwVmq1DyqrRYwsBDRnE82Zw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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