SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '76696a02e79802231b37ac1faa5ceab08b6214ba7923598ed58565dbc06c7ab1' 
  AND token = 'y1C8Re8lhRp0YRoOUsq2pNhpjEsVaki9rlNXcfMwr1s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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