SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65ffc1db666f14a8bcce0c6360fc91bc2c78aeb7d3238ebb4cee0fd1760d224d' 
  AND token = 'dSrYaANUuyv3Hjm+8170urjLzLiYracwbAldvP5aMj4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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