SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29c264ce435d9e9ce973cf1e9a7e716a603221c5207eeca03ea4956b957919f0' 
  AND token = 'K+1WyiDAoYGw10YoIPzIYIbebpljvVH3yC6inB31PU4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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