SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f00acdff2187ef90a7bf5b70a0b48e981f83d481799dbb57012928d333453551' 
  AND token = 'oiPcPMjVNPqv2wUqrvNrAD7KVgUVwT+82LtNgRhJeTA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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