SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0535f94ad9376920d3fcb971efc6c688f49af8fa774336d77ddac6fe020e8bd' 
  AND token = 'sGQqqsIemWJr4TGibsW+Z6fjRwaMDOdXFwbgGEQ5VHg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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